/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.transforms.windowing;



import com.google.auto.value.AutoValue;

import com.bff.gaia.unified.sdk.annotations.Internal;

import org.joda.time.Duration;

import org.joda.time.Instant;



import java.io.Serializable;



/**

 * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>

 *

 * <p>An abstract description of a standardized transformation on timestamps.

 */

@Internal

public abstract class TimestampTransform implements Serializable {



  TimestampTransform() {}



  /**

   * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>

   *

   * <p>Returns a transform that shifts a timestamp later by {@code delay}.

   */

  @Internal

  public static TimestampTransform delay(Duration delay) {

    return new AutoValue_TimestampTransform_Delay(delay);

  }



  /**

   * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>

   *

   * <p>Returns a transform that aligns a timestamp to the next boundary of {@code period}, starting

   * from {@code offset}.

   */

  @Internal

  public static TimestampTransform alignTo(Duration period, Instant offset) {

    return new AutoValue_TimestampTransform_AlignTo(period, offset);

  }



  /**

   * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>

   *

   * <p>Returns a transform that aligns a timestamp to the next boundary of {@code period}, starting

   * from the start of the epoch.

   */

  @Internal

  public static TimestampTransform alignTo(Duration period) {

    return alignTo(period, new Instant(0));

  }



  /**

   * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>

   *

   * <p>Represents the transform that aligns a timestamp to the next boundary of {@link

   * #getPeriod()} start at {@link #getOffset()}.

   */

  @Internal

  @AutoValue

  public abstract static class AlignTo extends TimestampTransform {

    public abstract Duration getPeriod();



    public abstract Instant getOffset();

  }



  /**

   * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>

   *

   * <p>Represents the transform that delays a timestamp by {@link #getDelay()}.

   */

  @Internal

  @AutoValue

  public abstract static class Delay extends TimestampTransform {

    public abstract Duration getDelay();

  }

}